Method for applying high luster coating to tablets

ABSTRACT

A METHOD OF IMPARTING A HIGH LUSTER COATING TO INGESTIBLE TABLETS IS CARRIED OUT BY COATING WITH A LIQUID COMPOSITION WHICH IS 30-40% POWDERED CARNAUBA WAX, 10-20% WAX WHITE AND 40-60% METHYLCHLOROFORM OR PETROLEUM BENZIN.

Unitcd States Patent 3,576,665 METHOD FOR APPLYING HIGH LUSTER COATINGTO TABLETS Allan H. Cheiken, Elkins Park, and Joseph F. Bavitz, WillowGrove, Pa., assignors to Merck & Co., Inc., Rahway, NJ. No Drawing.Filed July 1, 1968, Ser. No. 741,274 Int. Cl. B44d 1/02; A61]; 9/00 U.S.Cl. 117-100 1 Claim ABSTRACT OF THE DISCLOSURE A method of imparting ahigh luster coating to ingestible tablets is carried out by coating witha liquid composition which is 30-40% powdered carnauba wax, 10-20% waxwhite and 40-60% methylchloroform or petroleum benzin.

PRIOR .ART

Remingtons Practice of Pharmacy and Pharmaceutical Sciences 13th ed.pages 598-599 contains related prior art.

This invention relates to a liquid wax and the techniques used inapplying this mixture to sugar and film coated tablets in order toinduce a high luster onto the tablets thereby improving the elegance ofthis finished product.

It is a generally acknowledged fact that a shiny surface on a tabletmakes it more acceptable to the consumer. A dull surface creates anunfavorable impression to the point that some consumer will unthinkinglyconclude that the tablet and its contents are of a low quality. This isespecially true of pharmaceutical tablets but it applies as well totablets in general such as candy and chewing gum tablets. A high lustertherefore induces the consumer to place a higher intrinsic 'value on thetablet.

In the past the luster of film coated tablets has been achieved by aso-called dry polishing operation in which the tablets, in a drycondition, are dusted with a dry, ground wax mixture and thencontinually rubbed against each other in a conventional tumbling barrel.This constant frictional contact serves to achieve a generalizedpolishing eifect but the resulting tablets failed to attain a highdegree of luster.

Sugar coated tablets, on the other hand, require a very criticalso-called set-up step during the process just prior to the applicationof the dry waxes in order to finally achieve a high luster. The use ofthe liquid wax mixture induces a high luster onto film coated tabletsand eliminates the set-up in the sugar coating process.

The composition which is applied to the tablets has the followingrelative proportions on a weight basis:

TABLE Percent Carnauba wax powdered 30-40 Wax white USP 10-20 Solvent40-60 "ice The solution is applied at room temperature to the tablets ina tumbling barrel by pouring it onto them. It is applied eithercontinuously or discontinuously and at such a rate that one to two ml.per kg. of tablets is applied in 10 minutes.

The amount applied per tablet will average less than 1 mg. for a /8"diameter tablet and a smaller or larger tablet will require acorresponding amount based on its surface area. Usually, the totalapplication time will be 35 to 45 minutes, at the rate stated above, andthereafter a final drying period may be expedited by a blast of warmeddrying air as in conventional practice.

Representative examples are the following:

EXAMPLE 1 Ten kilos of pharmaceutical tablets having a conventionalsugar coating and which were in diameter and thick were placed in atumbling barrel and rotated at 25 r.p.m. 15 ml. of a previously preparedsolution by weight of 35% powdered carnauba wax, 15% wax white USP and50% methylchloroform was poured onto the sloping surface of the tablets.The tablets continued to tumble for 10 minutes at which time a secondapplication of 15 ml. was applied. After 10 additional minutes oftumbling, 15 ml. of the solution was again applied and the tabletsrolled for an additional 20 minutes. The tablets were removed and foundto have a very high luster. Each tablet had an outer shiny coating.

EXAMPLE 2 Conventional sugar coated chewing gum tablets of the Chicletstype are put in the tumbling barrel and the process of Example 1 iscarried out. The tablets will be found to be extremely shiny.

EXAMPLE 3 The process of Example 1 was carried out but petroleum benzinwas substituted for the methylchloroform. The same high luster wasproduced.

EXAMPLE 4 The process of Example 1 is carried out using variouscompositions in the ranges of the above table and were found to have thesame high luster.

EXAMPLE 5 The process of Example 1 is carried out several times,applying the solution at the rate of only 1 ml. in ten minutes and at 2ml. in ten minutes. The application times were varied from 35 to 45minutes and in all instances the same ultra shiny surface will appear.

EXAMPLE 6 The process of claim 1 is carried out using tablets which hadbeen film coated with conventional synthetic resins and the sameextremely high luster is imparted. These film coatings were theconventional ones such as are described in Pats. 3,383,236; 3,379,554;3,112,220; 3,325,365 and 3,275,518, and the references cited in themdisclosing synthetic film forming coatings.

EXAMPLE 7 The process of Example 1 is carried out as a supplement toordinary coating without removal of the tablets from the coating pan.For instance, after a conventional sugar or synthetic coating has beenapplied to tablets in a conventional tablet tumbling pan the tablets areallowed to remain therein and vyith or wi thout 's topping' the panrotation, the process of this invention is carried out.

What is claimed is:

1. The method of imparting a high luster t0 ingestible tablets 'whichcomprises applying to them a composition consisting essentially of byweight, 30-40% powdered earnauba Wax, 1020% Wax White and 4060% of asolvent selected from the group consisting of methylchloroform andpetroleum benzin, at the rate of 1 to 2 ml. per kg. in 10 minutes over a35 to 45 minute period, and drying said tablets.

References Cited UNITED STATES PATENTS 3 141,722. 174 264., with; i x

' 3,145,146 "8/1964'"iieliernian'ef'ali TIT- lOOX FOREIGN' PATENTS256,128 4/1963 Australia 117100 683,244 3/1964 Canada 117100 OTHER REFERENCES Hackhs Chemical Dictionary, 4th ed., p5 87. I Remingtons Practiceof Pharmacy & Pharmaceutical Sciences, 13th ed., pp. 598-99. V

WILLIAM ID. MARTIN, Primary Examiner M. R. P. PERRONE, JR.', AssistantExaminer Us. 01. X.R.

